Media independent trigger model for multiple network types

ABSTRACT

A media independent trigger model for multiple network types is disclosed. A change in communication environment trigger is communicated from a media dependent interface to an upper media independent application. The communication environment trigger may be from a local event detected by the interface or may be a remote trigger received from another device. The upper media independent application adjusts operations according to the communication environment trigger.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/982,228, now issued as U.S. Pat. No. 7,684,342, filed Nov. 3, 2004,and claims priority to that date.

BACKGROUND Description of the Related Art

In advancing communication technology, a single device may be able tocommunicate over two or more different kinds of wired or wireless links.Each of these links may implement a different link protocol, anddistinct types of hardware and software may be used to support thevarious protocols. The networks formed by the different types of linksmay be heterogeneous networks, meaning that the hardware and softwareassociated with one of the links might not be usable to make connectionsacross another link. Some of the networks formed by the different typesof links may be homogeneous links, but may have different accessparameters, including operator or carrier differences, access point orbase station differences, encoding differences, and the like.

As a mobile device roams from one location to another, properties of thecommunication networks in the environment change. For example, thestrength of a wireless signal may decrease as the mobile device moves,away from another device and eventually become too weak to communicateproperly. Thus, the mobile device may need to switch communicationlinks, for example, from a WiFi network to a WiMax network or from oneaccess point to another access point.

Changes in the properties of communication networks or links, forexample, a decrease in signal strength, an increase in noise, a decreasein throughput, and the like, are easily detected at media dependentlayers such as a physical (PHY) layer and/or a media access control(MAC) layer. Higher layers, such as a transport layer and an applicationlayer, are media independent and applications operating here typicallycan not detect changes in the properties of different communicationnetworks or links. A higher layer application may notice lack ofreceived packets and initiate a large timeout counter. Upon timeout, theunavailability of the current link is apparent and adaptive action istaken. A technique is needed to make applications at higher mediaindependent layers quickly and accurately aware of changes in thecommunication environment.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 illustrates a block diagram of a communication system withmultiple wired and wireless networks according to an embodiment of thepresent invention.

FIG. 2 illustrates a network independent trigger model according to anembodiment of the present invention.

FIG. 3 illustrates a flow diagram performed by a media dependentinterface of a device according to an embodiment of the presentinvention.

FIG. 4 illustrates another flow diagram performed by a media dependentinterface of a device according to an embodiment of the presentinvention.

FIG. 5 illustrates a flow diagram performed by a media independentapplication of a device according to an embodiment of the presentinvention.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DESCRIPTION OF THE EMBODIMENT(S)

In the following description, numerous specific details are set forth.However, it is understood that embodiments of the invention may bepracticed without these specific details. In other instances, well-knownmethods, structures and techniques have not been shown in detail inorder not to obscure an understanding of this description.

References to “one embodiment,” “an embodiment,” “example embodiment,”“various embodiments,” and the like, indicate that the embodiment(s) ofthe invention so described may include a particular feature, structure,or characteristic, but not every embodiment necessarily includes theparticular feature, structure, or characteristic. Further, repeated useof the phrase “in one embodiment” does not necessarily refer to the sameembodiment, although it may.

As used herein, unless otherwise specified the use of the ordinaladjectives “first,” “second,” “third,” and the like, to describe acommon object, merely indicate that different instances of like objectsare being referred to, and are not intended to imply that the objects sodescribed must be in a given sequence, either temporally, spatially, inranking, or in any other manner.

Unless specifically stated otherwise, as apparent from the followingdiscussions, it is appreciated that throughout the specificationdiscussions utilizing terms such as “processing,” “computing,”“calculating,” or the like, refer to the action and/or processes of acomputer or computing system, or similar electronic computing device,that manipulate and/or transform data represented as physical, such aselectronic, quantities into other data similarly represented as physicalquantities.

In a similar manner, the term “processor” may refer to any device orportion of a device that processes electronic data from registers and/ormemory to transform that electronic data into other electronic data thatmay be stored in registers and/or memory. A “computing platform” maycomprise one or more processors.

Types of communication systems intended to be within the scope of thepresent invention include, although not limited to, Local Area Network(LAN), Ethernet, Wireless Local Area Network (WLAN), Wireless Wide AreaNetwork (WWAN), Wireless Personal Area Network (WPAN), WirelessMetropolitan Area Network (WMAN), Code Division Multiple Access (CDMA)cellular radiotelephone communication systems, Global System for MobileCommunications (GSM) cellular radiotelephone systems, North AmericanDigital Cellular (NADC) cellular radiotelephone systems, Time DivisionMultiple Access (TDMA) systems, Extended-TDMA (E-TDMA) cellularradiotelephone systems, third generation (3G) systems like Wide-bandCDMA (WCDMA), CDMA-2000, Universal Mobile Telecommunications System(UMTS), and the like, although the scope of the invention is not limitedin this respect.

FIG. 1 illustrates a block diagram of a communication system withmultiple wired and wireless networks according to an embodiment of thepresent invention. In the system 100 shown in FIG. 1, a first device 110may include a wireless transceiver 112 to couple to one or more antennas114 and to a baseband processor 116. Baseband processor 116 in oneembodiment may include a single processor, or alternatively may includea baseband processor and an applications processor, although the scopeof the invention is not limited in this respect. Baseband processor 116may couple to a memory 118 which may include volatile memory such asDRAM, non-volatile memory such as flash memory, or alternatively mayinclude other types of storage such as a hard disk drive, although thescope of the invention is not limited in this respect. Some portion orall of memory 118 may be included on the same integrated circuit asbaseband processor 116, or alternatively some portion or all of memory118 may be disposed on an integrated circuit or other medium, forexample a hard disk drive, that is external to the integrated circuit ofbaseband processor 116, although the scope of the invention is notlimited in this respect.

First device 110 communicates to a second device 120 and a third device130, at least one of the three may be a mobile unit (MU). Second device120 may include a transceiver 122, one or more antennas 124, basebandprocessor 126, and memory 128. Third device 130 may include atransceiver 132, one or more antennas 134, baseband processor 136, andmemory 138.

First device 110, second device 120, and third device 130 may be any ofvarious devices, such as a cellular telephone, wireless telephoneheadset, printer, wireless keyboard, mouse, wireless network interfacedevices and network interface cards (NICs), base stations, access points(APs), gateways, bridges, hubs, cellular radiotelephone communicationsystems, satellite communication systems, two-way radio communicationsystems, one-way pagers, two-way pagers, personal communication systems(PCS), portable or stationary personal computers (PCs), personal digitalassistants (PDAs), software defined radios, reconfigurable radios, orother device capable of communicating over a wireless network.Additionally or alternatively, in other embodiments of the presentinvention, communication system 100 may include additional devices, anyof which may be mobile units.

In some embodiments, first device 110, second device 120, and thirddevice 130 may transmit and/or receive one or more packets over system100 via antennas 114, 124, and 134. In addition, first device 110,second device 120, and third device 130 may include two or more antennasto provide a diversity antenna arrangement, to provide spatial divisionmultiple access (SDMA), or to provide a multiple input, multiple output(MIMO) system, or the like, although the scope of the invention is notlimited in this respect. The packets may include data, control messages,network information, and the like.

Second device 120 may be coupled with network 140 wired or wirelessly sothat first device 110 and second device 120 may communicate with network140, including devices coupled to network 140. Network 140 may include apublic network such as a telephone network or the Internet, oralternatively network 140 may include a private network such as anintranet, or a combination of a public and a private network, althoughthe scope of the invention is not limited in this respect. Third device130 may also couple with network 140. Second device 120 and/or thirddevice 130 may be network attachment points, for example, access points,base stations, and the like, though the invention is not limited in thisrespect. For example, second device 120 and/or third device 130 may beother wired or wireless devices with indirect network access.

First device 110 and second device 120 may communicate with each othervia one of multiple wireless communication links, for example links 152,154, and 156. First device 110 and third device 130 may communicate witheach other via wireless communication link 158. Each of these links mayimplement a different wireless air link protocol, and distinct types ofhardware and software may be used to support the various protocols. Forexample, transceiver 112 and antennas 114 may include multipletransceivers and antennas for communicating via the multiple wirelesscommunication links. The choice of which communication link to use maybe determined based on proximity to the other device, strength of asignal, available bandwidth, cost of wireless spectrum, user or systemlevel policies, and other such conditions.

Note that first device 110 is illustrated as being capable ofcommunicating according to three or more wireless networks, seconddevice 120 is illustrated as being capable of communicating according tothree wireless networks and a wired network (to network 140), and thirddevice 130 is illustrated as being capable of communicating according toone wireless network and a wired network. Each device may be capable ofcommunicating according to any number of wired or wireless networks, theinvention is not limited in this scope.

Links 152, 154, 156, and 158 may be implemented in accordance withvarious wireless standards including, for example, one or more wirelesscellular standards, one or more wireless networking standards, one ormore radio frequency identification (RFID) standards, and/or others.Some of the different networks formed by links 152, 154, 156, and 158may be heterogeneous networks, meaning that the hardware and softwareassociated with one of the links cannot typically be used to makeconnections across another link. In at least one implementation, forexample, at least one link is implemented in accordance with theBluetooth short range wireless protocol (Specification of the BluetoothSystem, Version 1.2, Bluetooth SIG, Inc., November 2003, and relatedspecifications and protocols). Other possible wireless networkingstandards include, for example: IEEE 802.3, IEEE 802.11 (ANSI/IEEE Std802.11-1999 Edition and related standards), IEEE 802.16, HIPERLAN 1, 2and related standards developed by the European TelecommunicationsStandards Institute (ETSI) Broadband Radio Access Networks (BRAN),HomeRF (HomeRF Specification, Revision 2.01, The HomeRF TechnicalCommittee, July, 2002 and related specifications), and/or others. Someof the different networks formed by links 152, 154, 156, and 158 may behomogeneous links, but may have different access parameters, includingoperator or carrier differences, access point or base stationdifferences, encoding differences, and the like. For example, networksformed by links 156 and 158 may be IEEE 802.11 networks but havedifferent access parameters, for example, as two different access pointsand/or two different operators/carriers.

In one embodiment of the present invention, first device 110communicates with second device 120 via wireless link 152. If thecommunication environment changes, for example, if first device 110 is amobile device and begins moving out of a range capable of communicatingvia link 152, first device 110 may begin communicating, for example,with second device 120 via link 154 or with third device 130 via link158. In an alternate embodiment of the present invention, second device120 may disconnect a wired connection to network 140 and need to begincommunicating wirelessly. In each of these situations, the change in theinterface environment needs to be communicated to upper mediaindependent applications such that appropriate action can be taken. Amedia independent trigger is generated at a media dependent layer andcommunicated to upper media independent application levels.

Upper media independent applications may use the trigger information todetermine a new optimum communication link. Other applications may usethe trigger information to adjust communication parameters, for example,by adjusting the size of packets sent and the communication frequency,or by ceasing communication during a link handover.

A generalized trigger model provides abstraction for communicationenvironment events. Communication environment events are communicated toupper layer applications as a trigger in a common format acrossdifferent types of networks. Thus, media independent applications areable to interface with lower layer media dependent functions (MAC andPHY) in a consistent manner across multiple different media types.

Trigger events may be deterministic or predictive. Deterministic triggerevents may indicate current link status such as link up or link down.Link up status communicates, for example, that the physical link isconnected at the media dependent layer and that media independentapplications can begin communications. Link down status communicates,for example, that the physical link is down at the media dependent layerand that the media independent layer should cease communications. Adeterministic trigger event may also indicate current status of anotherlink. For example, a management trigger indicating that another link isavailable may be sent from the network, for example, an access point.The other link, to for example, another access point, may be moreoptimal than the link currently used by a device. Predictive triggerevents may indicate a future, predicted link status such as link goingdown or link going up. Link going down status indicates, for example,that based on decaying signal strength and the like, a loss of linkconnectivity is expected in a certain amount of time. Link going upstatus indicates, for example, that the physical layer connectivity isexpected to be available in a certain amount of time. Although fourtrigger events are described, other trigger events may also begenerated, for example, link available and other such events. Theinvention is not limited in this respect.

FIG. 2 illustrates a network media independent trigger model 200according to an embodiment of the present invention. A first device 202communicates with a second device 204 via a communication link 206.Communication link 206 may be a wired or a wireless link. First device202 includes a physical (PHY) layer 212, a media access control (MAC)layer 214, a media independent handover function 216, an Internetprotocol (IP) application 218 and one or more other applications, 220.Second device 204 includes similar, but not necessarily the same layers,a physical (PHY) layer 222, a media access control (MAC) layer 224, amedia independent handover function 226, an Internet protocol (IP)application 228 and one or more other applications, 230. PHY layers 212and 222 and MAC layers 214 and 224 are considered media dependent layersbecause these layers implement the communication or network specificmedia interface and are different for different communication media. Forexample, a WiMax media interface operates according to differentparameters and protocols than a WLAN media interface and the associatedPHY and MAC layers are different. Layers above PHY and MAC layers areconsidered media independent layers because the applications thatoperate at these levels are independent of the type of communicationmedia.

In one embodiment of the present invention, PHY layer 212 and/or MAClayer 214 of first device 202 detect a change in environment on link206. PHY layer 212 and/or MAC layer 214 generate a media independenttrigger. The trigger is media independent such that PHY or MAC layersassociated with different communication media generate a similarlyformatted trigger. The trigger is sent to applications in upper layers,for example, MIH function 216, IP application 218, and/or otherapplications 220. These applications at upper layers adjust theiroperations accordingly. For example, MIH function 216 may determine anew link for communication, IP application 218 may cease communicationsfor a period of time, and the like.

In another embodiment of the present invention, a remote trigger isgenerated by second device 204. This trigger may be generated by one ofthe media independent applications or by MAC layer 224 or PHY layer 222.The remote trigger is packaged and sent to first device 202 via link206. PHY layer 212 and/or MAC layer 214 receives the remote trigger andsends it to the upper media independent applications of first device202.

The trigger is media independent allowing higher layer applications toreceive trigger events in a consistent manner across differentcommunication media. Thus higher layer applications need to support asingle trigger/event interface for all communication media.

FIG. 3 illustrates a flow diagram 300 performed by a media dependentinterface of a device according to an embodiment of the presentinvention. A device communicates with another device via a first linkduring normal operation, block 302. A media dependent interface detectsa change in the interface environment of the first link, for example, achange in signal strength, a decrease in data throughput, an increase innoise, and the like, block 304. The media dependent interface generatesa media independent trigger, block 306 and sends the trigger to an uppermedia independent application, block 308. The media dependent interfacereceives instructions from the upper layer application, for example, toswitch to a second link with the other device or a second link with adifferent device, block 310.

In an alternate embodiment of the present invention, instructions arenot received from an upper layer application and the media dependentinterface automatically switches links. The upper layer applicationsreceiving a trigger adjust operations as needed.

FIG. 4 illustrates a flow diagram 400 performed by a media dependentinterface of a device according to an embodiment of the presentinvention. A device communicates with another device via a first linkduring normal operation, block 402. The other device may be a mobiledevice, a network entity such as an assess point or a base station, andthe like. A media dependent interface receives a media independenttrigger on the first link from the other device, block 404. The mediadependent interface sends the remote trigger to an upper layer mediaindependent application, block 406. The media dependent interfacereceives instructions from the media independent application to affect achange to the first link, for example, to switch to a second link, block408.

FIG. 5 illustrates a flow diagram 500 performed by a media independentapplication of a device according to an embodiment of the presentinvention. A media independent application receives a media independenttrigger indicating a change in interface environment from a lower mediadependent interface, block 502. The media independent applicationdetermines a different link for communication, block 504. In thisdetermination, the media independent application may determine whetherthe link was locally or remotely generated, the type of trigger, anddetermine a best available link. The media independent application sendsinstructions to the lower layer media dependent interface to affect achange in the communication link, block 506.

The techniques described above may be embodied in a computer-readablemedium for configuring a computing system to execute the method. Thecomputer readable media may be permanently, in a removable manner, orremotely coupled to first device 110, second device 120, third device130 or another system. The computer readable media may include, forexample and without limitation, any number of the following: magneticstorage media including disk and tape storage media; optical storagemedia such as compact disk media (for example, CD-ROM, CD-R, and thelike) and digital video disk storage media; holographic memory;nonvolatile memory storage media including semiconductor-based memoryunits such as FLASH memory, EEPROM, EPROM, ROM; ferromagnetic digitalmemories; volatile storage media including registers, buffers or caches,main memory, RAM, and the like; and data transmission media includingpermanent and intermittent computer networks, point-to-pointtelecommunication equipment, carrier wave transmission media, theInternet, just to name a few. Other new and various types ofcomputer-readable media may be used to store and/or transmit thesoftware modules discussed herein. Computing systems may be found inmany forms including but not limited to mainframes, minicomputers,servers, workstations, personal computers, notepads, personal digitalassistants, various wireless devices and embedded systems, just to namea few. A typical computing system includes at least one processing unit,associated memory and a number of input/output (I/O) devices. Acomputing system processes information according to a program andproduces resultant output information via I/O devices.

Realizations in accordance with the present invention have beendescribed in the context of particular embodiments. These embodimentsare meant to be illustrative and not limiting. Many variations,modifications, additions, and improvements are possible. Accordingly,plural instances may be provided for components described herein as asingle instance. Boundaries between various components, operations anddata stores are somewhat arbitrary, and particular operations areillustrated in the context of specific illustrative configurations.Other allocations of functionality are envisioned and may fall withinthe scope of claims that follow. Finally, structures and functionalitypresented as discrete components in the various configurations may beimplemented as a combined structure or component. These and othervariations, modifications, additions, and improvements may fall withinthe scope of the invention as defined in the claims that follow.

1. An apparatus comprising: a media independent application at anapplication layer; an interface to communicate an interface environmentchange with a first device and with the media independent application;the interface further to communicate an interface environment changetrigger to a media independent handover function between the interfaceand the media independent application in response to the interfaceenvironment change; and the media independent application further toreceive the interface environment change trigger and to adjustoperations based on the interface environment change trigger; whereinthe interface includes MAC and PHY layers.
 2. The apparatus as recitedin claim 1, wherein the interface environment change trigger isgenerated from a remote trigger event received from the first device. 3.The apparatus as recited in claim 1, wherein the interface environmentchange trigger is generated from a local event detected by theinterface.
 4. The apparatus as recited in claim 3, wherein the localevent is a decrease in signal strength of a signal from the firstdevice.
 5. The apparatus as recited in claim 1, wherein the interfaceenvironment change trigger indicates a current status of a link betweenthe interface and the first device.
 6. The apparatus as recited in claim5, wherein the current status of the link indicates that the link is up.7. The apparatus as recited in claim 5, wherein the current status ofthe link indicates that the link is down.
 8. The apparatus as recited inclaim 1, wherein the interface environment change trigger indicates afuture predictive status of a link between the interface and the firstdevice.
 9. The apparatus as recited in claim 8, wherein the futurepredictive status of the link indicates that the link is going up. 10.The apparatus as recited in claim 8, wherein the future predictivestatus of the link indicates that the link is going down.
 11. Theapparatus as recited in claim 1, wherein the interface communicates tothe first device via a first link, wherein the interface environmentchange trigger indicates that a second link is available forcommunication.
 12. The apparatus as recited in claim 1, wherein toadjust operations comprises to cause a change in communication from thefirst device to a second device.
 13. The apparatus as recited in claim1, wherein to adjust operations comprises to cause a change incommunication from one type of communication system to another type ofcommunication system, the communications systems to be coupled to theinterface.
 14. The apparatus as recited in claim 1, wherein theinterface is to communicate with the first device via a plurality oftypes of communication systems and the interface environment changetrigger is to be received by the media independent application in thesame format regardless of the type of communication system, thecommunication systems to be coupled to the interface.
 15. A methodcomprising: receiving, by a wireless communication device, acommunication of an interface environment change from a first device viaa first communication link; sending an interface environment changetrigger from MAC and PHY layers to a media independent handover functionbetween the MAC and PHY layers and a media independent application layerin response to the interface environment change; and receiving, by themedia independent application, the interface environment change triggerand to adjust operations based on the interface environment changetrigger.
 16. The method as recited in claim 15, further comprising:detecting an environment change event on the first communication link;and generating the interface environment change trigger.
 17. The methodas recited in claim 16, wherein the environment change event is adecrease in signal strength of a signal from the first device.
 18. Themethod as recited in claim 15, further comprising receiving theinterface environment change trigger from the first device.
 19. Themethod as recited in claim 15, further comprising receiving instructionsfrom the media independent application to change communication with thefirst device to a second communication link.
 20. The method as recitedin claim 15, further comprising receiving instructions from the mediaindependent application to change communication to a second device. 21.The method as recited in claim 15, wherein the interface environmentchange trigger indicates a current status of the first communicationlink.
 22. The method as recited in claim 15, wherein the interfaceenvironment change trigger indicates a future predictive status of thefirst communication link.
 23. The method as recited in claim 15, whereinthe interface environment change trigger indicates that a secondcommunication link is available for communication.
 24. An articlecomprising a computer-readable medium having stored thereoncomputer-executable instructions that, when executed by at least oneprocessor, cause operations comprising: receiving, by a wirelesscommunication device, a communication of an interface environment changefrom a first device via a first communication link; sending an interfaceenvironment change trigger from PHY and MAC layers to a mediaindependent handover function between the MAC and PHY layers and a mediaindependent application layer in response to the interface environmentchange; and receiving, by the media independent application, theinterface environment change trigger and to adjust operations based onthe interface environment change trigger.
 25. The article as recited inclaim 24, the operations further comprise: detecting an environmentchange event on the first communication link; and generating theinterface environment change trigger.
 26. The article as recited inclaim 25, wherein the environment change event is a decrease in signalstrength of a signal from the first device.
 27. The article as recitedin claim 24, wherein the operations further comprise receiving theinterface environment change trigger from the first device.
 28. Thearticle as recited in claim 24, wherein the operations further comprisereceiving instructions from the media independent application to changecommunication with the first device to a second communication link. 29.The article as recited in claim 24, wherein the operations furthercomprise receiving instructions from the media independent applicationto change communication to a second device.
 30. The article as recitedin claim 24, wherein the interface environment change trigger indicatesa current status of the first communication link.
 31. The article asrecited in claim 24, wherein the interface environment change triggerindicates a future predictive status of the first communication link.32. The article as recited in claim 24, wherein the interfaceenvironment change trigger indicates a second communication link isavailable for communication.
 33. A system comprising: one or moreantennas; a media independent application at an application layer; aninterface to communicate an interface environment change with a firstdevice via the one or more antennas and with the media independentapplication; the interface further to communicate an interfaceenvironment change trigger to a media independent handover functionbetween the interface and the media independent application in responseto the interface environment change; and the media independentapplication further to receive the interface environment change triggerand to adjust operations based on the interface environment changetrigger; wherein the interface includes MAC and PHY layers.
 34. Thesystem as recited in claim 33, wherein the interface environment changetrigger is generated from a remote trigger event received from the firstdevice.
 35. The system as recited in claim 33, wherein the interfaceenvironment change trigger is generated from a local event detected bythe interface.
 36. The system as recited in claim 33, wherein theinterface environment change trigger indicates a current status of asignal received on the one or more antennas from the first device. 37.The system as recited in claim 33, wherein the interface environmentchange trigger indicates a future predictive status of a signal receivedon the one or more antennas from the first device.
 38. The system asrecited in claim 33, wherein to adjust operations comprises to cause achange in communication from the first device to a second device. 39.The system as recited in claim 33, wherein to adjust operationscomprises to cause a change in communication from one type ofcommunication system to another type of communication system, thecommunication systems to be coupled to the interface.